package com.hmdp.service.impl;


import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@RequiredArgsConstructor
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    private final ISeckillVoucherService seckillVoucherService;
    private final RedisIdWorker redisIdWorker;
    private final StringRedisTemplate stringRedisTemplate;
    private final RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
//            while (true) {
//                try {
//                    // 1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 >
//                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
//                            Consumer.from("g1", "c1"),
//                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
//                            StreamOffset.create("stream.orders", ReadOffset.lastConsumed())
//                    );
//                    // 2.判断订单信息是否为空
//                    if (list == null || list.isEmpty()) {
//                        // 如果为null，说明没有消息，继续下一次循环
//                        continue;
//                    }
//                    // 解析数据
//                    MapRecord<String, Object, Object> record = list.get(0);
//                    Map<Object, Object> value = record.getValue();
//                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
//                    // 3.创建订单
//                    createVoucherOrder(voucherOrder);
//                    // 4.确认消息 XACK
//                    stringRedisTemplate.opsForStream().acknowledge("s1", "g1", record.getId());
//                } catch (Exception e) {
//                    log.error("处理订单异常", e);
//                    //处理异常消息
//                    handlePendingList();
//                }
//            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    // 1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create("stream.orders", ReadOffset.from("0"))
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有异常消息，结束循环
                        break;
                    }
                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    // 3.创建订单
                    createVoucherOrder(voucherOrder);
                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge("s1", "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理pendding订单异常", e);
                    try{
                        Thread.sleep(20);
                    }catch(Exception es){
                        es.printStackTrace();
                    }
                }
            }
        }
    }


//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//    private class VoucherOrderHandler implements Runnable {
//        public void run() {
//            while (true) {
//                try {
//                    //1 获取队列中的订单信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //2 创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常", e);
//                }
//            }
//        }
//
//    }
    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
//        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        if (!isLock) {
            //获取锁失败  返回错误信息
            log.error("不允许重复下单");
            return;
        }

        try {
            //获取代理对象（事务）
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }
//    @Override
//    public Result setkillVoucher(Long voucherId) {
//        //1 查询优惠卷
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//
//        //2 判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            //尚未开始
//            return Result.fail("秒杀尚未开始");
//        }
//
//        //3 判断秒杀是否已经结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束");
//        }
//
//        //4 判断库存是否充足
//        if (voucher.getStock() < 1) {
//            //库存不足
//            return Result.fail("库存不足");
//        }
//
////        baseMapper.insert(voucherOrder);
//        //7 返回订单id
//        Long userId = UserHolder.getUser().getId();
//        //创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            //获取锁失败  返回错误信息
//            return Result.fail("一个人只能买一件商品呦");
//        }
//
//        try {
//            //获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            lock.unlock();
//        }
//
//    }

    private IVoucherOrderService proxy;

    @Override
    public Result setkillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        //1 执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId)
        );

        int r = result.intValue();
        //2 判断是否为零0
        if (r != 0) {
            //2.1 不为零没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //3 返回订单id
        return Result.ok(0);
    }
//    @Override
//    public Result setkillVoucher(Long voucherId) {
//        //获取用户
//        Long userId = UserHolder.getUser().getId();
//        //1 执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(), userId.toString()
//        );
//
//        int r = result.intValue();
//        //2 判断是否为零0
//        if (r != 0) {
//            //2.1 不为零没有购买资格
//            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
//        }
//
//        //2.2 为零有购买资格  把下单信息保存到阻塞队列
//        VoucherOrder voucherOrder = new VoucherOrder();
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        //放入阻塞队列
//        orderTasks.add(voucherOrder);
//
//        //获取代理对象
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//
//        //3 返回订单id
//        return Result.ok(0);
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = UserHolder.getUser().getId();
        synchronized (userId.toString().intern()) {
            // 5.1.查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder).count();
            // 5.2.判断是否存在
            if (count > 0) {
                // 用户已经购买过了
                log.error("用户已经购买过一次了");
                return ;
            }

            // 6.扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1") // set stock = stock - 1
                    .eq("voucher_id", voucherOrder).gt("stock", 0) // where id = ? and stock > 0
                    .update();
            if (!success) {
                // 扣减失败
                log.error("库存不足");
                return ;
            }

            // 7.创建订单
            save(voucherOrder);
        }
    }
}
